Marsupials are naturally restricted to Australia and South America, yet comparative biochemical analysis reveals near-identical amino acid sequences in their cytochrome c proteins. Which of the following best explains this observation?
- The organisms share a common ancestor that inhabited the unified landmass prior to continental separationCevap
- BThe organisms independently evolved identical amino acid sequences as an adaptive response to similar climatic environments
- CThe organisms acquired identical protein alterations during their lifespan due to environmental stress from continental movement
- DThe organisms represent extreme ends of continuous variation within a single geographically continuous population
Cevap
The organisms share a common ancestor that inhabited the unified landmass prior to continental separation.
High sequence homology in essential proteins such as cytochrome c demonstrates close genetic relationship. When combined with biogeographical evidence showing Australia and South America were once joined as part of Gondwana, it indicates that marsupial ancestors lived on the shared landmass before continental drift isolated them.
Adım Adım Çözüm
Anahtar Kavram
Biogeographical disjunct distribution combined with molecular protein homology provides evidence of common ancestry prior to continental drift.